How to call a class from a project to another project without call the DLL as reference in C#?

I have three parts of a project, one is Core(bussiness) project, one is webproject and the last is the test project.

I want to call some classes that I saved in one folder from core project to webproject without calling the dll of the core project. Since core project is already refereed into the webproject. So it will call the cycling if the references and not allow me to do that.

How I can use classes from core project to web project without call the DLL? I Have already tried 'using', The code is following. It's not working for me.

using BlogEngine.Core.API.PageML; // I need to call all classes from this folder
using BlogPage = BlogEngine.Core.API.PageML;
namespace admin.Settings
{
 public partial class DownloadInsertPage : System.Web.UI.Page{
  protected void BtnPageMLInsertClick(object sender, EventArgs e)
  {
   var reader = new PageReaders(); // the class, I want to call from the core project
  }
}

Thanks